
You only need to use one of them for a texture pack. The normal version must have dumped when either arbitary mipmaps was disabled or GPU texture decoding was enabled, and the arb version must have dumped when arbitrary mipmaps was enabled and GPU texture decoding disabled. Disabling arbitrary mipmap detection, or turning on GPU Texture decoding, disables arbitrary mipmap detection, which is why you have two versions of the texture. are exactly the same texture, except Dolphin has determined that it has mipmaps that differ from the top level. It is independent from the other two, and needs to be retextured.

is a version of the texture without mipmaps.
